Internal exposure to polychlorinated dibenzo-p-dioxins and polychlorinateddibenzofurans (PCDDs/PCDFs) of Bavarian chimney sweeps

This study was carried out to evaluate the internal exposure to polychlorin ated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) of c himney sweeps in Bavaria compared to a control group without occupational e xposure. The PCDD/PCDF concentrations in the blood fat of 227 chimney sweep s were compared with the concentrations in samples from 60 controls. Using an internal standard containing 17 C-13(12)-labeled PCDD/F congeners, the s amples were cleaned up after fat elution using standard methods. The statis tical analysis was adjusted to account for demographic differences, dietary habits, smoking status, and both occupational and nonoccupational contact with chlorinated hydrocarbons. Detailed information on the type of heating in the households swept, the length of time the chimney sweeps had carried out the profession (min 34, med 195, max 466 months) and the protective mea sures employed, were used to examine the influence of the working condition s specific to chimney sweeps on the internal PCDD/PCDF exposure. The correl ation be tween blood-fat PCB concentrations as well as urinary chlorophenol concentrations and the exposure to PCDDs/PCDFs was evaluated. The sum of P CDD/PCDF components in chimney sweeps, expressed by international Toxic Equ ivalents (I-TEQ), was significantly increased compared to the control group (median: 26.36 versus 20.75 pg I-TEQ/g blood fat). For 37 chimney sweeps ( 16.3%) the sum of PCDDs/PCDFs exceeded the 95th percentile of the control g roup, i.e., 38.23 pg I-TEQ/g blood fat. Multiple regression analysis reveal ed that in addition to occupation, the variables age, district, and proximi ty to a waste incineration plant seem to have an effect on the internal PCD D/PCDF exposure. An additional influence on the internal exposure could not be determined for any of the special aspects of the work. We identified no high correlations between the concentrations of PCBs and chlorophenols and PCDDs/PCDFs. This study revealed significantly higher internal exposure to PCDDs/PCDFs in chimney sweeps than in the control group. The differences a re small and within the range of the internal exposure to PCDDs/PCDFs in bl ood found in the general population in Germany since 1989. Further investig ations in to PCDD/PCDF-related diseases in these study groups were not carr ied out.